OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LTC4308IMS8#TRPBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16
LTC4308
1
4308f
Low Voltage, Level Shifting
Hot Swappable 2-Wire Bus
Buffer with Stuck Bus Recovery
The LTC
®
4308 hot swappable, 2-wire bus buffer allows
I/O card insertion into a live backplane without corrup-
tion of the data and clock busses. The LTC4308 provides
bidirectional buffering, keeping the backplane and card
capacitances isolated. Negative offset from output to
input allows communication between output bus devices
with high V
OL
and devices on the low voltage input side,
where bus supplies can be as low as 0.9V. If SDAOUT or
SCLOUT are low for 30ms, the LTC4308 will automati-
cally break the Input-Output connection. At this time the
LTC4308 automatically generates up to 16 clock pulses
on SCLOUT in an attempt to free the bus. A connection
will resume if the stuck bus is cleared.
During insertion, the SDAOUT and SCLOUT lines are pre-
charged to 1V to minimize bus disturbances. When driven
high, the ENABLE input allows the LTC4308 to connect after
a stop bit or bus idle condition. Driving ENABLE low breaks
the connection between SDAIN and SDAOUT, SCLIN and
SCLOUT. READY is an open-drain output which indicates
that the backplane and card sides are connected.
n
Live Board Insertion
n
Servers
n
Capacitance Buffer/Bus Extender
n
RAID Systems
n
ATCA
n
Optimized for Low Voltage Systems Down to 0.9V
n
Bidirectional Buffer with Stuck Bus Recovery
n
–200mV Offset In-Out/+300mV Offset Out-In
n
30ms Stuck Bus Timeout
n
Compatible with Non-Compliant V
OL
I
2
C Devices
n
Prevents SDA and SCL Corruption During Live
Board Insertion and Removal from Backplane
n
±6kV Human Body Model (HBM) ESD Protection
n
Isolates Input SDA and SCL Lines from Output
n
Compatible with I
2
C™, I
2
C Fast Mode and SMBus
n
READY Open-Drain Output
n
1V Precharge on SDAOUT and SCLOUT Lines
n
Small 8-Lead (3mm × 3mm × 0.75mm) DFN and
8-Lead MSOP Packages
1.2V to 5V Level Shifting
The LTC4308 in a 1.2V
Microcontroller Application
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Hot Swap
is a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents including 7032051, 6650174, 6356140.
V
CC
5V
1.2V
2.7k
LTC4308
SCLIN
SDAIN
SCLOUT
SDAOUT
CARD_SCL
READY
CARD_SDA
READY
GND
ENABLE
2.7k 2.7k
10k
4308 TA01a
2.7k
MICRO-
CONTROLLER
0.01μF
1μs/DIV
2V/DIV
CH1
0.5V/DIV
CH2
4308 TA01b
SDAOUT
SDAIN
LTC4308
2
4308f
V
CC
to GND ................................................. – 0.3V to 6V
SDAIN, SCLIN, SDAOUT, SCLOUT,
READY, ENABLE .......................................... –0.3V to 6V
Maximum Sink Current (SDAIN, SCLIN, SDAOUT,
SCLOUT, READY) .............................................. 50mA
Operating Temperature Range
LTC4308C ................................................ 0°C to 70°C
LTC4308I..............................................– 40°C to 85°C
(Notes 1, 7)
The
l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
CC
= 3.3V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply
V
CC
Positive Supply Voltage
l
2.3 5.5 V
I
CC
Supply Current V
CC
= 5.5V, V
SCLOUT
= V
SDAOUT
= 0V (Note 6)
l
711mA
I
SD
Shutdown Supply Current V
CC
= 5.5V, ENABLE = 0V
l
900 1400 μA
V
PRE
Precharge Voltage SDAOUT, SCLOUT Open
l
0.8 1 1.2 V
Storage Temperature Range
DFN ....................................................– 65°C to 125°C
MSOP ................................................– 65°C to 150°C
Lead Temperature (Soldering, 10 sec)
MSOP ............................................................... 300°C
ORDER INFORMATION
TOP VIEW
9
DD PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
5
6
7
8
4
3
2
1ENABLE
SCLOUT
SCLIN
GND
V
CC
SDAOUT
SDAIN
READY
T
JMAX
= 125°C, θ
JA
= 43°C/W
EXPOSED PAD (PIN 9) CONNECTION TO GROUND IS OPTIONAL
1
2
3
4
ENABLE
SCLOUT
SCLIN
GND
8
7
6
5
V
CC
SDAOUT
SDAIN
READY
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 125°C, θ
JA
= 200°C/W
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC4308CDD#PBF LTC4308CDD#TRPBF LBTT 8-Lead (3mm × 3mm) Plastic DFN 0°C to 70°C
LTC4308IDD#PBF LTC4308IDD#TRPBF LBTT 8-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C
LTC4308CMS8#PBF LTC4308CMS8#TRPBF LTBTS 8-Lead Plastic MSOP 0°C to 70°C
LTC4308IMS8#PBF LTC4308IMS8#TRPBF LTBTS 8-Lead Plastic MSOP –40°C to 85°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *Temperature grades are identifi ed by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based fi nish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
ELECTRICAL CHARACTERISTICS
LTC4308
3
4308f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t
IDLE
Bus Idle Time
l
55 95 175 μs
V
THR_EN
ENABLE Threshold Voltage ENABLE Rising Edge
l
0.45 0.6 0.75 V
V
THR_EN(HYST)
ENABLE Threshold Voltage Hysteresis (Note 3) 35 mV
I
ENABLE
ENABLE Input Current ENABLE from 0V to V
CC
l
0.1 ±5 μA
t
PLH_EN
ENABLE Delay Off-On (Figure 1) 95 μs
t
PHL_EN
ENABLE Delay On-Off (Note 3), (Figure 1) 10 ns
t
PLH_READY
READY Delay Off-On (Note 3), (Figure 1) 10 ns
t
PHL_READY
READY Delay On-Off (Note 3), (Figure 1) 10 ns
V
OL_READY
READY Output Low Voltage I
READY
= 3mA, V
CC
= 2.3V
l
0.4 V
I
OFF_READY
READY Off Leakage Current V
CC
= READY = 5.5V
l
0.1 ±5 μA
Prop Delay and Rise-Time Accelerators
t
PHL
SDA/SCL Propagation Delay High to Low C
LOAD
= 50pF, 2.7k to V
CC
on SDA, SCL,
(Notes 2, 3), (Figure 1)
70 ns
t
PLH
SDA/SCL Propagation Delay Low to High C
LOAD
= 50pF, 2.7k to V
CC
on SDA, SCL,
(Notes 2, 3), (Figure 1)
10 ns
t
RISE
SDA/SCL Transition Time Low to High C
LOAD
= 100pF, 10k to V
CC
on SDA, SCL,
(Notes 3, 4), (Figure 1)
30 300 ns
t
FALL
SDA/SCL Transition Time High to Low C
LOAD
= 100pF, 10k to V
CC
on SDA, SCL,
(Notes 3, 4), (Figure 1)
30 300 ns
I
PULLUPAC
Transient Boosted Pull-Up Current Positive Transition > 0.8V/μs on SDAOUT,
SCLOUT (Note 5)
58 mA
Input-Output Connection
V
OS
Input to Output Offset Voltage (OUT – IN) 2.7k to V
CC
on SDAOUT, SCLOUT,
SDAIN = SCLIN = 0.2V
l
250 300 380 mV
2.7k to V
CC
on SDAOUT, SCLOUT,
SDAIN = SCLIN = 0.4V, V
CC
= 5.5V
l
250 350 450 mV
Output to Input Offset Voltage (IN – OUT) 2.7k to V
CC
on SDAIN, SCLIN,
SDAOUT = SCLOUT = 0.4V
l
–150 –200 –300 mV
2.7k to V
CC
on SDAIN, SCLIN,
SDAOUT = SCLOUT = 0.4V, V
CC
= 5.5V
l
–150 –250 –350 mV
V
THR
SDAOUT, SCLOUT Logic Input Threshold Voltage V
CC
≥ 2.9V
V
CC
< 2.9V
1.4
1.1
1.65
1.35
1.9
1.6
V
V
SDAIN, SCLIN Logic Input Threshold Voltage SDAIN, SCLIN Rising Edge, V
CC
= 2.3V, 5.5V 0.45 0.6 0.75 V
V
THR(HYST)
SDAOUT, SCLOUT Logic Input Threshold Voltage
Hysteresis
(Note 3) 50 mV
SDAIN, SCLIN Logic Input Threshold Voltage
Hysteresis
(Note 3) 35 mV
C
IN
Digital Input Capacitance SDAIN, SDAOUT,
SCLIN, SCLOUT
(Note 3) 10 pF
I
LEAK
Input Leakage Current SDA, SCL Pins
l
±5 μA
V
OL
Output Low Voltage SDAOUT, SCLOUT Pins, I
SINK
= 4mA,
SDAIN = SCLIN = 0V, V
CC
= 2.7V
l
0 400 mV
2.7k to V
CC
on SDAOUT, SCLOUT,
SDAIN = SCLIN = 0V
l
250 300 380 mV
V
ILMAX
Buffer Input Logic Low Voltage SDAOUT, SCLOUT Pins
l
1.2 V
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
CC
= 3.3V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16

LTC4308IMS8#TRPBF

Mfr. #:
Buy LTC4308IMS8#TRPBF
Manufacturer:
Analog Devices Inc.
Description:
Interface - Signal Buffers, Repeaters Low Offset Hot Swappable Bus Buffer
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet